温度对双低两用核不育水稻96-5-2S与培矮64S育性的影响

Temperature Effects on Fertility of Rice TGMS Line Between 96-5-2S with Double Low Critical Temperature Values and Peiai 64S

在自然变温、人工控温及冷水灌溉条件下 ,比较研究了温度对双低两用核不育水稻 96 -5 -2 S与两用核不育水稻培矮6 4 S育性影响的差异。结果表明 :1当它们在雄性育性转换温敏感期遇到 1～ 1 2 d平均自然日均温 2 3.0～ 2 3.8℃的低温时 ,96 -5 -2 S表现不育 ,套袋自交结实率为 0 ,而培矮 4 6 S可育 ,套袋自交结实率为 0 .1 %～ 4 .5 % ;2在它们雄性育性转换温敏感期用 2 2℃恒温处理 5 d,96 -5 -2 S败育彻底 ,套袋自交结实率为 0 ,而培矮 6 4 S可育 ,套袋自交结实率为 1 0 .7% ;用1 7℃恒温处理 6 d,96 -5 -2 S与培矮 6 4 S均可育 ,但 96 -5 -2 S套袋自交结实率 ( 6 .8% )显著高于培矮 6 4 S( 2 .5 % ) ;3在它们雄性育性转换温敏感期用不同温度的冷水串灌 1 5 d,水深维持在 2 0 cm左右 ,当水温为 2 2～ 2 2 .5℃时 ,96 -5 -2 S不育 ,结实率为 0 ,而培矮 6 4 S可育 ,结实率为 1 8.5 % ;当水温为 1 9.5～ 2 1 .5℃时 ,96 -5 -2 S与培矮 6 4 S均可育 ,但 96 -5 -2 S结实率( 2 .5 %～ 4 5 .1 % )显著或极显著低于培矮 6 4 S( 5 0 .4 %～ 5 6 .9% )。以上结果说明 :导致双低两用核不育水稻 96 -5 -2 S雄性不育的起点温度与导致其生理不育的下限温度均低 ,其不育性比培矮 6 4 S更稳定 ,耐寒性比培矮 6 4

The commercial production of two line system hybrid rice deponds on development of a number of qualified photo- or thermo-sensitive genic male sterile ( PGMS & TGMS ) lines of rice .The most important criterion for qualified rice PGMS & TGMS lines is that the initial temperature inducing male sterility must be relatively low .The rice TGMS line 96-5-2S with double low critical temperature values ,i.e., both the initial temperature inducing male sterility and critical low temperature causing physiologically abortion are low,was developed through pureline selection from another rice TGMS line Peiai 64S which is widely used in China now.In order to know the sensitivity of its fertility to low temperature and its initial temperature inducing male sterility so as to put it into use, we studied the effects of temperature on its fertility compared with control rice TGMS line Peiai 64S under the conditions of natural changeable air temperature, artificially controlled air temperature, and cold water temperature. The results were as follows: ①When 96-5-2S and Peiai 64S met natural low air temperature of 23.0～23.8℃(average daily mean temperature) for 1～12 day( days) at their thermo-sensitive stages(stages of pollen mother cell formation and meiotic division of pollen mother cell) inducing male fertility alternation, 96-5-2S was sterile with bagged seed set of zero and stainable pollen grains of 0.0%～0.4%, significantly or very significantly different from those of Peiai 64S which was fertile with bagged seed set rate of 0.1%～4.5% and stainable pollen grains of 1.0%～8.6%(2-tailed independent sample t-test ,t=2.236～3.860,df =18,P<0.05 or P<0.01). ②Treated with controlled air temperature of constant 22℃ for 5 days at above sensitive stages, 96-5-2S was completely abortive without any bagged seed set and stainable pollen grains, very significantly different from those of fertile Peiai 64S with bagged seed set rate of 10.7% and stainable pollen grains of 26.7%(t=6.384～6.469,df =18, P<0.01); Treated with controlled air temperature of constant 17℃ for 6 days at the sensitive stages,both 96-5-2S and Peiai 64S were fertile, but the bagged seed set(6.8%) and stainable pollen grains (20.5%)of 96-5-2S was significantly higher than those of Peiai 64S (2.5% and 8.4% respectively)(t=2.748～2.780,df =18 P<0.05).③Irrigating consecutively with cold water of different temperature at the same sensitive stages for 15 days and keeping water depth in the paddy fields about 20 cm, 96-5-2S was sterile with seed set of zero if the irrigating water temperature was 22℃ or more, very significantly different from that of fertile Peiai 64S with seed set rate of 18.5%(t=6.710,df =18, P<0.01); if the irrigating water temperature ranged from 19.5 ～21.5℃, both of them were fertile, but the seed set rate of 96-5-2S was 2.5%～45.1%,significantly or very significantly lower than that of Peiai 64S whose seed set rate was 50.4%～56.9%(t=2.650～ 31.813 ,df =18, P<0.05 or P<0.01). Based on above results, it is concluded that the sterility of rice TGMS line 96-5-2S is more stable than that of rice TGMS line Peiai 64S ,its initial temperature inducing male sterility is less than 23℃(daily mean temperature ) or 22℃ (constant temperature),obviously lower than that of Peiai 64S ,and its chilly-resistance is stronger than that of Peiai 64S , its critical low temperature value causing physiologically abortion is less than 17℃ .Therefore, it is safe to produce two line system hybrid rice seed with it, and it can multiply itself, eventually, it will play an important role in developing two-line system hybrid rice.